Float valve for dry washing machines

ABSTRACT

A program controlled dry cleaning machine employing low boiling point solvents, and comprising a cleaning chamber, a solvent feeding tank, a soiled solvent still connected to a first solvent vapor condenser, a drying circuit comprising means for circulating hot air through the cleaning chamber and through a second solvent vapor condenser, the said vapor condensers being connected to the solvent feeding tank. The switching from one step to the following of the washing program is controlled on a time basis. A flowmeter is provided for sensing the flow of the solvent from said second condenser to the feeding tank, for controlling the duration of the drying step as a function of said flow.

ilmted States Patent [191 [111 3,757,542

Carpigiani 1 Sept. 11, 1973 FLOAT VALVE FOR DRY WASHING 3,392,580 7/1968 Bain et al 73 215 MACHINES 3,678,750 7/l972 DiNoia et al. 73/DIG. 5

[76] Inventor: lggeiziongalrtgilglam, Anzola Emilia, Primary Examiner john Petrakes g y Assistant Examiner-Philip R. Coe [22] Filed: Nov. 19, 1971 Att0rneyEdwin E. Greigg Appl. No.: 200,340

[57] ABSTRACT A program controlled dry cleaning machine employing low boiling point solvents, and comprising a cleaning chamber, a solvent feeding tank, a soiled solvent still connected to a first solvent vapor condenser, a drying circuit comprising means for circulating hot air through the cleaning chamber and through a second solvent vapor condenser, the said vapor condensers being connected to the solvent feeding tank. The switching from one step to the following of the washing program is controlled on a time basis. A flowmeter is provided for sensing the flow of the solvent from said second condenser to the feeding tank, for controlling the duration of the drying step as a function of said flow.

2 Claims, 3 Drawing Figures Patented Sept. 11, 1973 3,757,542

2 Sheo ts-ShocL L Patented Sept. 11, 1973 2 Sheets-Sheet 2 FLOAT VALVE FOR DRY WASHING MACHINES BACKGROUND OF THE INVENTION The invention relates to a machine for the dry cleaning of textiles by means of low boiling point solvents, of the kind comprising a dry-cleaning chamber housing a rotatable perforated drum, a soiled solvent recovery plant, and a drying plant for extracting the solvent which impregnates the washed textiles at the end of the washing cycle.

A machine of the kind to which the present invention relates is for instance described in my US. Pat. application Ser. No. 10,453, filed Feb. 11, 1970 and now US. Pat. No. 3,610,002.

The different operational steps of a machine of the aforementioned kind, that is the admission of the solvent in the cleaning chamber, the washing time, the centrifuge time, the discharge of the solvent, the distillation of the soiled solvent and the drying of the impregnated washed textiles are controlled by a suitable programming device.

Generally, the switching from one step to the following of the programmed cycle is controlled on a time basis, by means of a timer mechanism, taking into account the maximum time which could be requested for fully performing a certain operation.

The time requested for forming the operational steps above listed, with the exception of the drying step, may be considered a constant.

On the contrary, the time requested for the drying of the washed textiles may vary within ample limits, as a function of the absorption characteristics of the treated textiles, of the weight of the batch of textiles treated, and so on.

This means that the time which must be programmed for the drying operation greatly exceeds the average drying time. This means that the drying step is unduly lengthened, with consequent increasing of the operational costs of the machine.

SUMMARY OF THE INVENTION It is therefore the object of the present invention to overcome the above inconveniences of the prior art dry cleaning machines, by providing, in a machine of the kind set forth, means for controlling the duration of the drying step as a function of the effective drying of the goods being cleaned, as sensed by a flow of condensed solvent vapors to a solvent feed tank.

According to the invention, this is accomplished'by providing, in the discharge pipe from the vapor condenser of the drying circuit of the machine, a flowmeter controlling the programmer of the machine.

Advantageously,.the flowmeter is in the form of a box provided with an inlet and an outlet port, and with a dam extending transversally of the flow direction, and provided with at least one calibrated port formed below its upper edge, a float being slidably housed between said dam and the inlet port, said float cooperating with at least one switching member, for controlling the end of the drying step of the cleaning program as soon as the whole of the solvent has been removed from the goods being cleaned, as evidenced by the fact that no more solvent is condensed out from the air which is circulated through the drying flow cycle.

tion will become more apparent from the following description of a preferred embodiment, made with reference to the accompanying drawings, in which:

FIG. 1 is a diagrammatical representation of the solvent flow circuit of a dry cleaning machine according to the invention.

FIG. 2 is a diagrammatical representation of the cleaning program of the machine according to FIG. 1.

FIG. 3 is a longitudinal sectional view of a flowmeter according to the invention, used in the machine of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE INVENTION With reference to FIG. 1 of the drawings, 1 is the dry cleaning chamber of a dry cleaning machine. Inside of chamber 1 a perforated drum 2 is rotatably housed. Chamber 1 is connected via pipe 3 with a solvent feed tank 4, and via pipe 7 with a soiled solvent tank 6. An electric heating element 5 is disposed inside of tank 6, which acts as a stiller for the soiled solvent discharged. The distilled solvent is passed through pipe 8, to the condenser 9, in which the solvent vapors are condensed to liquid solvent which is discharged, through pipe 10, into feed tank 4.

In order to recover the solvent which imbibes the cleaned goods in drum 2, the machine is provided with a drying circuit comprising a blower 11, which blows air through the heating element 12, and pipe 13 into the chamber 1. The solvent-vapors-enriched air is thereafter passed through pipe 16, into condenser 15, in which the solvent vapors are separated by condensation from the air stream. The air stream is returned to the blower 11, through pipe 14, whilst the condensed liquid solvent flows through pipe 17, and the flowmeter 18 to the solvent feed tank 4.

The flowmeter 18 is best shown in FIG. 3. With reference to FIG. 3, the flowmeter 18 comprises a box 19 provided with an inlet port 20 for connection to the liquid feed pipe 17 and with an outlet port 21. The box 19 is comparted into two chambers by a transversal dam 22 extending from the box bottom up to a certain height of box 19.

In proximity of its bottom end, the dam 22 is provided with a transversally drilled through bore 23. At right angles to bore 23, a second blind bore is drilled in dam 22, which extends from the top of dam 22 down to the bottom end thereof, crossing the bore 23. In line with this second bore, a through bore 27 is drilled in the box cover, through which a stem 25 is guided, which passes through the box internal space and through the vertical bore in dam 22. In the stem region passing through the bore 23, the stem 25 is provided with a diametrically drilled through bore 26 which is accurately calibrated so as to allow a predetermined flow of liquid to pass therethrough. The upper portion of stem 25 projecting outwardly of box 1 terminates with a control knob 28. In correspondence of bore 27, the upper part of box 1 is furthermore provided with a groove 31 in which a transversal pin 30 integral of stem 25 is fitted. A sealing ring 29 provides the seal between the stem 25 and the bore 27.

The internal chamber of box 19, which is arranged on the side being upstream of dam 22, in the liquid flow bottom of dam 22. The well 32 is closed at its bottom by a cover 33 provided centrally with a threaded through bore. A small tube 34 made of a non magnetic material passes through the bore in cover 33 and extends from well 32 inside of the box 19, up to nearly the opposite upper wall of the box 19. The tube 34 has its upper end closed. On that tube 34 a float member 37 is slidably guided to be freely movable along said tube. Inside of the float 37 a permanent magnet 38 is housed, cooperating with a magnet-sensitive transducer 35, which is housed within the tube 34. By 36 there are designated the electric leads from the transducer 35.

The operation of the above described machine will be now described with further reference to the program diagram of FIG. 2.

After the introduction of the textiles to be washed in drum 2, and the closure of chamber 1, the solvent is admitted from tank 4 through pipe 3, into chamber 1. This step which is marked A in the program diagram, is followed by the cleaning step B. Thereafter, the soiled solvent is discharged from chamber 1, through pipe 7 into the receiver still 6, (step C), and this solvent is subjected to distillation (step D). The distilled solvent vapors are condensed by condenser 9, and returned to tank 4. The duration of steps A to D is controlled in conventional manner by a programming timing device.

In the following drying step E, all the solvent which imbibes the textiles in chamber 1 is extracted by means of the heated air flow generated by the blower 11 and heating element 12, and circulated through pipe 13, chamber 1, pipe 16, condenser and pipe 14 and again to blower 11.

The duration of step E is controlled by the flowmeter 18, which as mentioned above is inserted in pipe 17, leading from condenser 15 to tank 4.

The operation of the flowmeter 18 is as follows:

At the beginning of step E, a great amount of solvent is flowing from condenser 15 to tank 4, over the flowmeter 18. The solvent fills by consequence the space upstream of dam 22, and the float 37 is raised at a certain level above the flowmeter bottom. As long as the float is in this raised position, the drying step is permitted to continue.

The float will be maintained in its elevated position as long as the solvent entering the flowmeter 18 is in excess of the solvent flowing out through the calibrated port 26 in dam 22.

Whenever this relationship is inverted, the float will begin to be lowered, until it comes into the well 32. At this moment, the drying operation is ended, and the transducer 35 will provide a signal stopping the drying operation of the machine.

Of course the invention is not limited to the described embodiment, and for instance it would be obvious that a plurality of transducers 35 may be accomodated inside of tube 34, in order to provide different controls according to different flow conditions in flowmeter 18.

I claim:

1. A dry cleaning machine employing low boiling point solvents and comprising: a cleaning chamber; a perforated revolving drum in said chamber; a solvent tank for feeding the solvent to said chamber; a soiled solvent tank for receiving the solvent from said chamber; heating elements in said soiled solvent tank for distilling the soiled solvent; a vapor condenser connected to said soiled solvent tank for condensing the solvent vapors distilled; and a drying circuit, said drying circuit comprising: means for circulating a hot air flow through said cleaning chamber and through a second vapor condenser, said vapor condensers being connected to the solvent feeding tank; and a flowmeter sensitive to the flow of liquid from said second condenser to said solvent tank, said flowmeter being disposed in the flow path from said second condenser to said solvent tank, for acting upon switch means which controls the operation of the machine according to a pre-set program to thereby stop the drying operation whenever substantially the whole solvent has been removed from the goods being dryed, said flowmeter comprises a box-like member provided with a liquid inlet port, a liquid outlet port, a dam extending transversally of said box between said inlet and outlet ports, the height of said darn being lower than the height of said box, a calibrated through bore in said dam, a well in the bottom of said box between said dam and the liquid inlet port, a float member in said well, and switch means operated by said float member.

2. A machine according to claim I, wherein said switch means within said flowmeter are magnetically operated and said float is provided with an operating magnet.

t t t a t 

1. A dry cleaning machine employing low boiling point solvents and comprising: a cleaning chamber; a perforated revolving drum in said chamber; a solvent tank for feeding the solvent to said chamber; a soiled solvent tank for receiving the solvent from said chamber; heating elements in said soiled solvent tank for distilling the soiled solvent; a vapor condenser connected to said soiled solvent tank for condensing the solvent vapors distilled; and a drying circuit, said drying circuit comprising: means for circulating a hot air flow through said cleaning chamber and through a second vapor condenser, said vapor condensers being connected to the solvent feeding tank; and a flowmeter sensitive to the flow of liquid from said second condenser to said solvent tank, said flowmeter being disposed in the flow path from said second condenser to said solvent tank, for acting upon switch means which controls the operation of the machine according to a pre-set program to thereby stop the drying operation whenever substantially the whole solvent has been removed from the goods being dryed, said flowmeter comprises a box-like member provided with a liquid inlet port, a liquid outlet port, a dam extending transversally of said box between said inlet and outlet ports, tHe height of said dam being lower than the height of said box, a calibrated through bore in said dam, a well in the bottom of said box between said dam and the liquid inlet port, a float member in said well, and switch means operated by said float member.
 2. A machine according to claim 1, wherein said switch means within said flowmeter are magnetically operated and said float is provided with an operating magnet. 